2013年2月19日 星期二

確認與退回


自動確認+將該session尚未確認一起確認
DML:Create、Alter、Drop



手動確認
Commite

手動退回
rollback



select * from dept;

update dept set manager_id = '0' ;

savepoint A;


update dept set manager_id = '99';

savepoint B;

rollback to savepoint B;

rollback to savepoint A;


savepoint A
已更新. 8 個資料列
savepoint B
倒回完成.
已更新. 8 個資料列
savepoint A
已更新. 8 個資料列
savepoint B
倒回完成.
倒回完成.

SQL語法處理的順位


Select >> 5

From >> 1

Where >> 2

Group by >> 3

Having  >> 4

Order by  >>6